Money must be sustainable to stand the test of time. Anything used as money must only consume a reasonable amount of resources whenever it is created, spent, or stored for the future. Peercoin is cryptocurrency, a type of digital-money. Through its innovative proof-of-work+proof-of-stake hybrid algorithm, Peercoin uses far less energy, has stronger security, and can operate in a more decentralized way than other types of money. With a market capitalization of over $145 Million USD, Peercoin is reshaping the currency landscape.